Converting an old 80's MTB to singlespeed, advise??

[cjs]

I have an old 80's Raleigh MTB, I've nicked the shifters and derailleurs for another bike, but rather than scrap the rest, I though I could convert to a singlespeed.

I will change the tyres to road and leave the V brakes in place.

Existing crankset is a Shimano triple, I guess 44/32/22 with a 9 speed cassette. I do have an adjustment slot in the frame for the back wheel so chain tensioning should be easy.

So what should I do? Best ratios to start? Can I just strip down my existing crankset to one chainring, if so 44T or 32T. What rear sprocket? I will leave the 9 speed cassette in place to start until I choose the right sprocket.

This will just be a toy, something to ride to the pub/shops on rather than using my expensive MTB, mostly flat roads with the odd gentle up hill.

[JPJ]

Your slot dropout frame will be fine for mounting a singlespeeded wheel and provide enough adjustment for chain tension, so that's all good.

You can get a single speed conversion kit from On One or Surly (see Chainreactioncycles or Charlie the Bike Monger for the latter option) which will include 16t cog and some spacers to fill the space the cassette would have been in. This also allows you to play with the spacers to get the correct chain line from the crankset.

With the crank the only thing you might need is shorter crank bolts (see Charlie as mentioned above) if you use just the middle ring.

As for the correct choice of chainring, it really depends on the terrain you're riding. Off road I use a 32:16 ratio, but on road either a 44:16 or a 42:16. Given you say it will be a pub/shops bike, then this may be the better option to stop you spinning out but it does depend on the local topography.

[cjs]

JPJ said:

Your slot dropout frame will be fine for mounting a singlespeeded wheel and provide enough adjustment for chain tension, so that's all good.

You can get a single speed conversion kit from On One or Surly (see Chainreactioncycles or Charlie the Bike Monger for the latter option) which will include 16t cog and some spacers to fill the space the cassette would have been in. This also allows you to play with the spacers to get the correct chain line from the crankset.

With the crank the only thing you might need is shorter crank bolts (see Charlie as mentioned above) if you use just the middle ring.

As for the correct choice of chainring, it really depends on the terrain you're riding. Off road I use a 32:16 ratio, but on road either a 44:16 or a 42:16. Given you say it will be a pub/shops bike, then this may be the better option to stop you spinning out but it does depend on the local topography.

Thanks for the info. http://www.charliethebikemonger.com is a great site, loads of helpful stuff.

Just looked at my existing Shimano SLX 300 Crankset and it's a 48/36/22 so I will probably go with the 36T middle ring and then try a 16T rear sprocket, that will give me 59 gear inches which should be fine for what I need.

Just need some decent weather so I can get out in the garden to start work!

[vrooom]

I converted mine to single speed. Best thing i ever done, very easy and more fun to ride.
I bought 1/32 16t freewheel.
(1/32 is width of tooth, 1/32 is MTB type width, 1/8 is thick bmx type tooths) and screwed it to my hub.
I run 40 / 16 gearings. I used my existing mtb gear sprocket by then.

you need to adjust the axle centering, to make the chain straight as possible to sprocket from rear freewheel. this is important.

you may need to re-dish the rear wheel. to make rim to be center on the hub instead of being offset to right?, for your brakes. I didnt bother with this one.

Edited by vrooom on Wednesday 27th October 12:34

[Digga]

FWIW, +1 for Charlie the Bikemonger.